The really strange thing about plants absorbing only red and blue (purple when mixed), is that there is more yellow and green light out there! Now thatâ??s weird! Our eyes learned to be more sensitive to green and yellow, but plants didn't. Turns out they think that there were actually plants able to absorb all that green and yellow sun light out there, and it was a purple plant! Our plants are only green because red and blue was the only useful light that came through the other plants for the ancestor of our plants (the ones we know and love) to absorb! Weird to think, if things had been different, the world leaders wouldnâ??t be as much concerned with converting to green energy as converting to purple energy.